Buck converters are typically used to regulate the voltage of a DC power supply. A multiphase buck converter has several phases connected in parallel, with each phase having a top switch and a bottom switch connected to an inductor. Such multiphase buck converters are well known in the art and are commonly used for providing regulated DC power to loads that require higher current, fast transient response, and high conversion efficiency, such as microprocessors, computer memories, computer graphic processors, telecommunications electronics, and field-programmable gate array and other integrated circuits.
The prior art has sought to increase conversion efficiency and improve transient response of a multiphase buck converter by coupling the inductors of multiple phases. Inductors with inverse coupling tend to decrease output current ripple and, therefore, reduce conduction loss in the switches. However, the extra conductor windings required for inductors with inverse coupling increases resistance of the inductors, which adversely affects the energy conversion efficiency. In another prior art, the woven topology of inductor core required for inductors with inverse coupling increases volume of the magnetic core, which increases power loss of magnetic core and adversely affects the energy conversion efficiency.
It is an objective of the present invention to provide a multiphase buck converter, or boost converter, or buck-boost converter, or buck derived converter, or boost derived converter, or buck-boost derived converter having inversely coupled inductors with exceptionally low winding resistance and small magnetic core volume. Such a voltage converter has exceptionally high current capability, high power conversion efficiency, and fast transient response.